
import java.util.*;
import java.io.*;public class Hashmap
{
	public static void main(String[] args)
	{
		HashMap<Integer,String>a=new HashMap<Integer,String>();
		{
			a.put(1,"one");
			a.put(2,"tow");
			a.put(3,"three");
			a.put(4,"four");
			a.put(4,"five");//最后一个起效
			System.out.println(a.containsKey(1));
			System.out.println(a.containsKey(6));
			System.out.println(a.get(2));
			System.out.println(a.size());
			for(int k:a.keySet())
			{
				String b=a.get(k);
				System.out.println(b);
			}
			System.out.println(a.entrySet());
		}
		
	}
}
